1. Field of the Invention
This invention relates to a switch, and more particularly to a selection switch which, at the time of inserting cassette tape such as a sound tape, a video tape, a magnetic tape or the like in an apparatus such as a tape recorder, a video tape recorder, a magnetic memory or the like, is adapted to select, identify or detect the type of tape received in the cassette and the like to automatically carry out a desired switch operation.
2. Description of the Prior Art
Identification of the type of a tape received in a cassette such as, for example, a chrome tape, a metal tape, a regular tape or the like, and discrimination as to whether there is a recording on the tape in the cassette, or the like has been conventionally carried out by altering the position of a recess formed on the rear surface of a cassette. For this purpose, an apparatus such as a tape recorder, a video tape recorder or the like is provided with selection switch mechanisms at positions thereof corresponding to recesses of a cassette inserted in the apparatus so that contacts of the switch may be actuated in response to the cassette insertion operation.
A conventional selection switch mechanism of such type is typically constructed in a manner as shown in FIG. 1. The mechanism comprises a plurality of selection switch bodies 21 provided independent from one another in, for example, a frame 16 of a tape recorder or the like and levers 22 corresponding to the switch bodies 21 and provided in proximity thereto. The moment of the end portion of each of the levers 22 due to a recess 4' formed on the rear surface of a cassette C' acts to actuate the switch body 21.
There are two kinds of cassettes with respect to the use of such recess. One is the type in which a recess 4' is initially opened. The other is the type in which the recess 4' is initially closed by a cover 23 so that the back surface of the cassette may be regarded as substantially flat and thereafter the cover is removed by bending to prevent the erasure of a recording on a tape and/or the re-recording on a tape (FIG. 2).
Unfortunately, cassettes for a recording tape and the like which are significantly different in depth l have been conventionally manufactured depending upon manufacturers, particularly, foreign manufacturers. Also, such cassettes are different in dimensions of the recess 4'. In order to account for such variations in dimensions among the cassettes, the conventional selection switch mechanism is constructed to allow the lever 22 to carry out a wide movement. However, such construction has disadvantages of not allowing a well defined and smooth switching operation and of requiring a large area for installation, so that the conventional selection switch is an obstacle to the miniaturization of an apparatus such as a tape recorder, a video tape recorder or the like.